# -*- coding: UTF-8 -*-
from typing import List

import leetcode_helper
from leetcode_helper import TestcaseHelper, SolutionBase, ListNode
from typing import Optional


class Solution(SolutionBase):
    # 解题的方法，命名和Leetcode的保持一致即可
    def deleteMiddle(self, head: Optional[ListNode]) -> Optional[ListNode]:
        if head.next is None:
            return None

        fast = head
        slow = head
        pre = None

        while fast and fast.next:
            fast = fast.next.next
            pre = slow
            slow = slow.next

        pre.next = pre.next.next

        return head


if __name__ == '__main__':
    solution = Solution()

    # 按照leetcode的题目说明，将基本的test case填入
    # 每条case的最后一个元素是正确的结果，即期待的结果
    # 使用元组来保存输入的数据，期待的结果
    testcases = [
        ([1, 3, 4, 7, 1, 2, 6], [1, 3, 4, 1, 2, 6]),
        ([1, 2, 3, 4], [1, 2, 4]),
        ([2, 1], [2])
    ]

    for case_item in testcases:
        # 获取测试用的case和期待的执行结果
        input1 = case_item[0]
        expect = case_item[len(case_item) - 1]

        exec_result = solution.deleteMiddle(leetcode_helper.array_to_list(input1))

        # 判断执行结果，输出提示信息
        check_result = solution.check_result(expect, leetcode_helper.list_to_array(exec_result))
        TestcaseHelper.print_case(check_result, case_item, exec_result)

